In orthopedic surgery one often finds it necessary to place a guide wire into a bone in a desired position and orientation. These guide wires may be needed to guide an osteotomy, a drill hole, the placement of a cutting jig, etc. A common challenge is that there are often many degrees of freedom (positions and angles in multiple planes) that must be simultaneously controlled. Commonly wire guides are placed on the bone to direct the placement of the guide wire, but this requires exposing the bone, often necessitating a large dissection. An alternative is to achieve guide wire placement using fluoroscopy with radiographic projection of an extracorporeal guide, thus avoiding the need for an incision to place the guide on bone. The challenge inherent in the use of fluoroscopy with an extracorporeal guide is the number of degrees of freedom that must be simultaneously controlled often requires multiple attempts at guide wire placement even by an experienced surgeon.
One example of an application that requires the placement of a guide wire into a bone at a precise position and orientation is the fixation of an intertrochanteric (IT) hip fracture. These fractures are commonly treated with internal fixation employing a sliding hip screw and side plate implant. Placement of the sliding hip screw is achieved using a cannulated technique in which a guide wire is drilled from the lateral femur across the femoral neck and into the femoral head. The position and orientation of the guide wire is controlled with the use of an angle guide. Typically, the angle guide is placed directly onto lateral cortex of the femur. Placement of the angle guide on the femur requires a large (e.g., 15-20 cm) incision through skin, subcutaneous tissue, fascia and muscle. A percutaneous technique (e.g., without initial incision) has been previously described and has been shown to result in less blood loss and operative time (Alobaid et al., J Orthop Trauma 18:207-212; Cheng et al., Surgical Innovation 18: 99-105; Ho et al., Int Orthop 33:555-560). However, this technique relies on freehand placement of the guide wire, which can be time consuming and technically demanding since instrumentation that would allow for the rapid, accurate, and repeatable placement of the guide wire does not exist.
In order to make the process of percutaneously placing a guide wire into bone at a desired position and orientation simple, rapid, accurate and repeatable, the present invention allows for each degree of freedom to be independently controlled and then fixed, e.g., the methods, devices, and systems of the present invention may help fix the position and/or angle of the guide wire with respect to the bone in a rapid, accurate, and repeatable manner. As a non-limiting example in the case of facilitating the treatment of an IT fracture, the methods, devices, and systems of the present invention may help fix the position and angle in the frontal and transverse planes for the guide wire used for sliding hip screw implantation. The present invention is not limited to applications related to fractures, e.g., IT fractures. The present invention may be used for any appropriate procedure or application in which a guide wire is to be placed at a prescribed position and orientation in a bone. Non-limiting examples of applications include the placement of guide pins for cannulated screws osteotomies, cutting jigs, fracture reduction and fixation, and the like. Furthermore, the devices and systems of the present invention are not limited to the particular configurations described herein. The parameters (e.g., sizes, angles, etc.), configurations, and uses of the systems and devices disclosed herein may be modified to accommodate the anatomic location and position/orientation requirements for which it is used.
Without wishing to limit the present invention to any theory or mechanism, it is believed that the systems, methods, and devices of the present invention create a minimally invasive means of properly placing a guide wire in a bone. The systems, methods, and devices of the present invention may help improve accuracy and repeatability when placing the guide wire in a bone. The systems, methods, and devices of the present invention may also help avoid putting multiple holes in the bone, which may help lessen the chance of a postoperative fracture. The systems, methods, and devices of the present invention may also help reduce incision size, surgery time, and possibly blood loss.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.